Furnace



UNITED STATES PATENT OFFICE.

EOKLEY B. COXE, OF DRIFTON, PENNSYLVANIA. I

FURNACE.-

SPECIFICATION formingpart 01' Letters Patent NO. 510,572, dated December12, 1893. Application filed J n15 10, 1893. Serial No. 479.988. (Nomodel.)

To all whom it may concern.-

Be it known that I, EOKLEY B. Come, a citizen of the United States,residing at Drifton, in the county of Luzerne and State of Pennsylvania,have invented certain new and useful Improvements in Furnaces, of whichthe following is a specification.

This invention relates to traveling-grate furnaces; the object being toprovide an improved furnace of that class adapted for burning two gradesof fuel at the same time.

My present invention is in the nature of an improvement on the furnacedescribed and claimed in Letters Patent No. 499,716, granted to me June20, 1893, to which reference may be had for a more particulardescription than is contained herein of certain details of the furnacemechanism not essential to these present improvements.

In the drawings accompanying and forming a part of this specification,Figure llis a sectional side elevation of a traveling-grate furnaceembodying my present improvements. Fig. 2 is a vertical transversesection on line a a Fig. 1, showing the parts at the left-hand of saidline as seen from a point at the right-hand thereof. Fig.3 is an endelevation of the furnace as seen from the righthand in Fig. Fig. 4 is aplan view of the furnace, certain parts being broken away down to thebroken line b 19?.

In Fig. l the furnace is shown supplied with fuel as when in operation.

Similar characters designate like parts in all the figures.

For illustrating the application and mode of operation of my presentimprovements, I have shown the same applied to the furnace which isdescribed and claimed in my aforesaid Letters Patent No. 499,716. Thisfurnace comprises a traveling grate and means for actuating the same,and has its furnacechamber 0, and also the grate-mechanism, incloscd bythe usual side-walls 2 and 4, and end-walls 3 and 5. The endless grate,designated in a general way by G, comprises the upper and lower runs, 9and 10, respectively; said upper run constituting the furnace-floorunder which is located the series of air-blast chambers, a, b, c, d,these being supplied by the air-pipes a, b, c, at, through a conduit, M,leading from a blower, air-compressor or other air-supply, not shown.The upper and lower runs, respectively, of the endless grate are shownsupported on guides, 18 and 18, and 19 and 19, respectively. Foractuating the traveling grate G, this is shown carried by thechain-wheels 12 and 14, which are supported on the shafts 13 and 15,respectively; and for revolving the one of the shafts and therebyactuating the grate, said shaft, 15, is shown furnished with theworm-wheel 40, which meshes with a worm, 41, on a drivingshaft, 42, thatis supported in bearings, 43, 43', and is driven by a driving-pulley,44, from some suitable .sonrce of power, not shown. These severaldetails belonging to the inventionbeing described and claimed in myaforesaid Letters Patent, a further description of the same is deemedunnecessary.

For delivering the regular or first supply of fuel to the endless grate,the furnace is or may be provided with the supply-hopper H, Whose'mouthor discharge-opening delivers the fuel directly onto thegrate, asillustrated in Fig. 1. Immediately rearward of said supply-hopperI-I,the furnace-chamber O is shown covered with a roof or arch,designated by A, in which an opening is made at 85 through which tosupply the grate with an additional quantity of fuel, usually of anothergrade.

Rearward of the furnace-roof A, an ordinary steam-boiler, B, is shown inplace for being heated by the gases from the furnace; but it will beunderstood that said gases may be conducted to a separate heat-usingfurnace, or that any other thing to be heated may be substituted for theboiler B, which for clearne'ss of illustration is omitted in Fig. 4.

As a means for regularly delivering the additional fuel-supply to thefurnace-chamber through the aforesaid opening 85, a feed-apparatus isshown set above said opening, and comprises a hopper, H suitablysupported, and a feed-wheel or bucket-wheel, W, set underneath saidhopper in position for receiving the fuel therefrom and delivering thesame in a falling stream, 86, into the furnacechamber, as fullyillustrated in Fig. 1. For actuating said feed-wheel, the shaft 84 ofsaid wheelis shown furnished with a pulley or chain-wheel, 96, which isconnected by a driving-band or chain, 97, with a chain-wheel,

95, fixed on the shaft 15. By making the wheels 95 and 96 of properrelative dimensions, any required speed may be imparted to saidfeed-wheel, for delivering to the furnace any required proportion of thesecondary fuel.

The operation of the furnace, except as to the secondary fuel-supply, issubstantially the same as illustrated and described in my aforesaidLetters Patent No. 499,716. The fuel in the hopper H is delivereddirectly to the grate, on which it is spread in a layer, and during theregular operation of the furnace is ignited at a point adjacent to orover the first air-blast chamber a, which chamber is, in practice,supplied with air at a moderate pressure. The air-blast chamber 1) isordinarily supplied with air at a considerably higher pressure, for thepurpose of increasing the combustion and raising the burning mass to ahigh temperature. During or immediately following the thorough ignitionof the layer 71 of fuel, the secondary supply of fuel is delivered tothe furnace-chamber, being deposited in a layer, 7 2. superimposed uponsaid ignited layer 71 of fuel from the hopper II. In practice, saidsecondary supply is intended to be of a relatively low grade, such, forinstance, as carbonaceous slates and min erals found in connection withveins of pure coal. The secondary fuel being delivered into the hotfurnace-chamber upon a bed of fuel already brought to a high state ofcombustion, the carbon is rapidly distilled therefrom and mingled withthe furnace-gases, to be consumed in the rearward portions of thefurnace-chamber; the refuse mineral being finally carried off with theashes and cinder from the higher grade of fuel forming the first layerupon the furnace-floor.

By means of the improved furnace hereinv described, carbonaceousminerals having a very low proportion of carbon may be advantageouslyutilized in connection with the ordinary grades of coal, even when suchminerals may not be capable by themselves of supporting combustion.

It will be remembered that in the furnace herein shown, when operated asdescribed in my aforesaid Patent No. 499,716, the air-pressures in thechambers c and d will (usually) be normally less than in the air-blastchamber b; but in the present instance, owing to the increased depth ofthe mass of fuel beyond the point where the secondary supply isdelivered to the grate, the air-pressures will ordinarily require to beincreased in one or more of said chambers, for forcing the air throughthe primary and secondary layers of fuel. In this connection it will beunderstood that the number and width of the successive air-blastchambers will be regulated according to the duty required of thefurnace.

The improved process herein described of utilizing carbonaceous mineralsby distributing and burning the same upon a bed of higher-grade fuelpreviously ignited, is reserved to constitute the subject-matter of aseparate application, Serial No. 481,526, filed July 26, 1893.

Having thus described my invention, I claim- 1. In a furnace, thecombination with a traveling grate and a fuel-supply therefor, and withmeans for supplying air to the grate, of a second fuel-supply inposition for delivering fuel to the grate at a point beyond the normalignition-line of the fuel first supplied, substantially as and for thepurpose set forth.

2. In a furnace, the combination with a traveling grate and the firstfuel-supply therefor, of the second fuel-supply located above the gratein advance of the first fuel-supply, a feed-wheel for delivering thesecond supply of fuel to the furnace, and means for actuating thefeed-Wheel and the traveling grate, substantially as described.

8. In a furnace, the combination with a traveling grate, of a primaryand a secondary fuel-supply set one in advance of the other fordelivering primary and secondary layers of fuel upon the grate, and aseries of variable-pressure air-blast apparatuses un-- dern eath thegrate, the first of which is located between said fuel-supplies, andothers of which are located in position for blowing the combined primaryand secondary layers of fuel, substantially as described.

4. In a furnace, the combination with a traveling grate, means fordelivering a first fuel-supply to the grate at one point in the lengththereof, one air-supply apparatus located in advance of said firstfuel-supply for operating on the first supply of fuel, means fordelivering a second fuel-supply to the grate at a point beyond saidfirst air-supply apparatus, and a second air-supply apparatus located inadvance of said second fuelsupply for operating on the combined suppliesof fuel, substantially as described.

5. In a furnace, the combination with a traveling grate, and with meansfor supplying air to the grate, of a multiplicity of fuel supplyapparatuses in position and arranged for delivering successive suppliesof fuel to the grate at successive points in the length thereof.

EOKLEY B. COXE.

Vitnesses:

STEWART F. MACFARLANE, ELLIOTT A. OBERRENDER.

IIO

